WhatsApp is a popular messaging app owned by Facebook Inc. had stated earlier that it will not work on phones which are very old. The deadline for this is June of 2017 which was later extended to December 2017.So the latest deadline for stopping WhatsApp's services on the listed type of phones is 31st of December 2017.The list of smartphones on to which WhatsApp service will not work are:-1. Blackberry 10 devices. Example: Blackberry Z10.2. Windows phones running Windows Phone OS 8.0 and earlier.3. Android phones running Android Gingerbread (2.3). Example: Samsung Young.4. Apple iPhones running ios 6. Example: iPhone 3GS.*These are the only Series of Smartphone for which the WhatsApp Support will end by end of the year 2017While there are two categories of smartphones for which WhatsApp support will end in the next year1. Nokia Phones running Symbian S60 series of Operating System will lose WhatsApp in June 2018. Example: Nokia C6.2. Nokia Phones Running Symbian S60 Series of Operating System will lose WhatsApp in December 2018. Example: Nokia X3 touch n type.*These deadlines are as stated on WhatsApp's official Blog.You can read this on WhatsApp Official Blog also.